Definition of halcyons:
(adj) :
(figurative) Calm, undisturbed, peaceful, serene.
(n) :
(poetic) A kingfisher whose nesting by the sea was said, in classical mythology, to cause the Gods to restrain the wind and waves.
(n) :
A tropical kingfisher of the genus Halcyon, such as the sacred kingfisher (Halcyon sancta) of Australia.
(adj) :
Pertaining to the halcyon or kingfisher.
(n) :
The dead body of such a bird, said in Tudor times to act as a weather vane when hung from a beam.